Nerves can be transected for a variety of reasons. Whether the nerve is transected deliberately or by accident, repair of the nerve can be facilitated if a nerve end is cut and free of frayed or damaged areas, or randomly extending axons and tissue. Clean nerve ends can be easier to coapt to other nerve ends or grafts and can promote alignment of the axons from each terminal nerve end. Also, nerve ends that are to be capped or covered can be easier to manipulate and development of neuromas can be minimized if the nerve end is free of randomly extending axons.
In order to obtain a clean cut nerve end, it may be necessary to resection the nerve tissue some distance away from the terminal end, to remove damaged or non-viable tissue at the terminal nerve end. Resection of nerve tissue can be difficult. If done incorrectly it can result in a new terminal nerve end that is crushed, frayed, or that has multiple transection lines caused by the cutting implement making multiple passes or sawing across the tissue. Properly bracing the circumference of the nerve in the area of transection can minimize such damage to the one or more new terminal nerve ends. There are devices that can be used to support a nerve, while a cutting implement is used to transect the nerve. Often these devices do not entirely brace the full circumference and secure the position of the nerve, thus, allowing the nerve to roll or turn during the cutting process. This can necessitate excessive force being applied by the cutting implement in order to hold the nerve while it penetrates the tougher outer epineurium. This force can crush the softer internal nerve tissues. Alternatively, a cutting implement may have to be passed through the tissue more than once to incrementally sever the nerve tissue, which can result in a frayed nerve end.
If the resected nerve end is to be coapted to, or inserted into, a graft or implant, the nerve must be measured in vivo, so that an appropriately-sized graft can be selected. It has been demonstrated that when obtaining sizes of nerves during surgical procedures, the measurements are usually inaccurate. Nerve tissue is soft and pliable and does not often have a defined diametric shape. As such, it can be difficult to visually estimate the size of a nerve or obtain an accurate measurement of the diameter when the nerve is placed on a flat measuring surface.
Every manipulation and change of equipment or tools that must be made during surgery takes time and increases the opportunities for error. Devices and surgical tools that have multiple functions are desirable, as they can reduce the number of manipulations necessary to complete a procedure.